hiive got a requirement to add a clock to a 328, so i need a battery backup for it if the power goes out just wondering what is the most common surface mount 100ma regulator i could use / most popular one. or maby is there a more suitable one that i could use for such a small current?

i did measure a single 328 running think it was about 15ma if i remember

my first choice would be a 78L05L just wondering if this is a common regulator

hiive got a requirement to add a clock to a 328, so i need a battery backup for it if the power goes out just wondering what is the most common surface mount 100ma regulator i could use / most popular one. or maby is there a more suitable one that i could use for such a small current?

i did measure a single 328 running think it was about 15ma if i remember

my first choice would be a 78L05L just wondering if this is a common regulator

thank you

What are your requirements for dropout voltage, etc.?

No, I don't answer questions sent in private messages (but I do accept thank-you notes...)

What is powering the circuit the rest of the time? You need to design it so that there is an orderly handover of power from the PSU to the battery. The usual solution is to feed the voltage regulator from the PSU through a diode and from the battery via another diode.

Formal verification of safety-critical software, software development, and electronic design and prototyping. See http://www.eschertech.com. Please do not ask for unpaid help via PM, use the forum.

Note - some of these parts have "unusual" pinouts. There are also a lot of smt v.regs that I wasn't interested in here.

Thermal resistance for TO-92 is 200 degC/W, so you have to be a little careful about overheating at the higher currents. Eg, with Pd = Vdrop * Iload = 0.5W, and you limit Vdrop to 0.5W/.25A = 2V, it'll still burn your finger.